Issue on startup

[BarryKH]

Once in a while when I start my 2013 Sierra SLE 5.3, it shudders and takes 3 or 4 seconds to start. Most of the time it is just normal starting, smooth and starts right up. I can't figure what it could be. Kinda reminds me of dieseling when shutting off, but this is when starting. Any ideas?

 

[diyer2]

My 2012 5.3 did this. I put new spark plugs in it. Had about 60 k miles on it. Also cleaned MAF. Fixed.

[BarryKH]

Thanks, I'll give it a try.